1. Field of the Invention
The present invention relates to biometric authentication.
2. Description of the Related Art
Biometric information-based authentication has been known as an individual identification technique. In 1:N authentication of biometric identification, there are possibilities of wrong rejection of an identical person and wrong authentication of other people (hereafter wrong rejection of the identical person and wrong authentication of other people are collectively referred to as “wrong identification”). The biometric information used for biometric authentication varies among different individuals. For example, the biometric information of some individuals may have a small amount of characteristic features or very simple characteristic features. Such biometric information may have significant contributions to wrong identification. One proposed method to reduce the potential risk of wrong identification compares the biometric information with registered data for matching and calculates an identification reference value according to the matching distribution (see, for example, JP 2000-215313).
This proposed method requires recalculation of the matching distribution in the case of an increase in number of registered data or in the case of transfer of registered data to another database. A change of the population of registered data may significantly change the user's convenience, for example, changing the identification reference value and the identification result or varying the processing time for individual identification.